Discusses sleep movements of Porlieria.

Has read an abstract of Julius Wiesner on heliotropism and geotropism ["Die heliotropischen Erscheinungen im Pflanzenreiche", Anz. Kais. Akad. Wiss. Wien 15 (1878): 137–40] which seems important but is puzzling.

Gives details of his observations on climbing plants with reference to comments by Julius Sachs.

Has offered Carl Semper the writing machine.

Speculates on the mechanism of movement in plants and their reception of and response to stimuli.

Is forwarding the writing machine to Carl Semper.

Is glad FD has taken up his old friends, the twiners.

Hopes to get heliotropic aerial roots from J. D. Hooker. Asks FD to find out whether any moulds or roots are apheliotropic. Is puzzled by heliotropism in subterranean roots.

Comments on function of bloom.

Describes the effect of water shortage on sleep movements in Porlieria.

Describes observations and experiments on the response to light of Bignonia capreolata tendrils.

Is pleased FD’s climbing work goes well.

Thanks him for information on heliotropism.

Discusses sleep movements

and his observations on the sensitivity of radicle tips.

Instructs FD to plant some Oxalis seeds.

Wishes to trace the movement of an old cotyledon. Asks him to examine and compare the pulvinus of a species which moves its cotyledon greatly with one of a species that moves it only moderately.

Are the tendrils ready for heliotropic experiment yet?

Instructions to sow some seeds

and suggestions for experiment on effects of removal of bloom.

Likes Hugo de Vries very much; has hardly ever seen so modest a man.

Asks FD to reply to a letter [11653a] requesting a list of CD’s books.

Julius von Sachs’s views on stomata seem largely correct, but CD cannot understand how leaves can survive submerged for such long periods.

Has been observing Drosera and concludes that none of the movement of the tentacles is caused by growth.

Suggests observations to show role of pulvinus in leaf movement.

Asks what position the sub-peduncles assume when the main flower peduncle of Oxalis is tied so as to be horizontal.

Asks whether FD can find some plants at Kew for CD to trace epinastic and hyponastic movements.

Instructs FD to make some observations on movement in Trifolium and Impatiens. Sends some seeds to be sown.

Suggests experiment to detect salts deposited on surface of leaves.

Wants FD to have another go at horse-chestnut radicles.

Requests some seeds.

Believes the leaves of Phyllanthus sleep like those of Cassia.

Circular about the distribution of the overplus of his income and advice on investment.

Is increasing FD’s allowance.

Has begun his chapter on sleep of plants [for Movement in plants].

CD cannot find his pincers and other tools for microscopical dissection. Does FD know where he should look?

Hopes FD will feel better after "so complete a change" [trip to North Africa].

Sends his love to George.

Bernard gets more charming every day.

CD has been put on a committee for a memorial fund for W. K. Clifford.

Try to find and read [a German] account of the fir-trees affected by some fungus which produces upright shoots. CD wants to know whether the case is same as what he has observed in the silver fir. Includes diagram.

Wants FD to find out what sort of man Ernst Krause is.

Thanks for FD’s letter describing microscopic work under experienced supervision.

Is glad to hear of C. E. Stahl’s objection to treating plants as mere machines.

Pleased that J. von Sachs has yielded on growth.

Perhaps Stahl will recognise whether the case of the silver fir is the same as that referred to in the German account [see 12074b].

CD has finished the first draft of his essay on Erasmus Darwin’s life and is "heartily sick of the job".